New Nitrogen-Rich Tripodal Molecules Based on Bis(pyrazol-1-ylmethyl)amines with Substituents Modulating Steric Hindrances and Electron Density of Donor Sites

2005 ◽  
Vol 70 (1) ◽  
pp. 34-40 ◽  
Author(s):  
Stefania Garbacia ◽  
Caroline Hillairet ◽  
Rachid Touzani ◽  
Olivier Lavastre
Keyword(s):  
Nmr Spectroscopy ◽  
Electron Density ◽  
Electron Donor ◽  
Primary Amines ◽  
Effect Of Substituents ◽  
H Nmr ◽  
Donor Acceptor ◽  
One Step ◽  
Steric Hindrances

Eight new substituted bis(pyrazol-1-ylmethyl)amines have been prepared in one step condensation of 1-(hydroxymethyl)-3,5-disubstituted pyrazoles with a series of primary amines. The effect of substituents of divers bulkiness and electron donor/acceptor power that have been introduced to these tridentate molecules is visualised by 1H NMR spectroscopy.

Demonstration of Diastereomeric Electron-Donor-Acceptor Complexes by1H-NMR Spectroscopy

1978 ◽  
Vol 17 (12) ◽  
pp. 940-942 ◽  
Author(s):  
Albrecht Mannschreck ◽  
Peter Roza ◽  
Hans Brockmann ◽  
Thorsten Kemmer
Keyword(s):  
Nmr Spectroscopy ◽  
Electron Donor ◽  
Donor Acceptor

Effect of lanthanide shift reagents on 1H NMR spectra of aminopyridines

1979 ◽  
Vol 44 (3) ◽  
pp. 908-911 ◽  
Author(s):  
Antonín Lyčka ◽  
Dobroslav Šnobl
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
Electron Donor ◽  
Electron Acceptor ◽  
Nmr Spectra ◽  
Pyridine Ring ◽  
Chemical Shifts ◽  
Amino Group ◽  
H Nmr ◽  
Lanthanide Shift Reagents

The effect of Eu(dpm)3 and Pr(dpm)3 on the proton spectra of 2-amino-, 3-amino- and 4-aminopyridines has been studied by the 1H NMR spectroscopy in tetrachlomethane and deuteriochloroform at 25 °C. Relative changes of the induced chemical shifts of pyridine carrying electron-donor substituents (amino group) are the same as the values given in literature for pyridine ring with electron-acceptor substituents.

scholarly journals Molecular motion of donor–acceptor catenanes in water

2015 ◽  
Vol 13 (10) ◽  
pp. 2927-2930 ◽  
Author(s):  
Fabien B. L. Cougnon ◽  
Nandhini Ponnuswamy ◽  
G. Dan Pantoş ◽  
Jeremy K. M. Sanders
Keyword(s):  
Nmr Spectroscopy ◽  
Molecular Motion ◽  
H Nmr ◽  
Donor Acceptor

In this article, we use 1H NMR spectroscopy to study the spontaneous molecular motion of donor–acceptor [2]catenanes in water.

Preparation and electron transfer-induced cis-trans isomerization reactions of 1-(5-nitro-2-furyl)-, 1-(5-nitro-2-thienyl)-, and 1-(4-nitrophenyl)-2-R ethylenes

1989 ◽  
Vol 54 (6) ◽  
pp. 1675-1682 ◽  
Author(s):  
Josef Prousek ◽  
Viktor Hayden
Keyword(s):  
Electron Transfer ◽  
Nmr Spectroscopy ◽  
Electron Donor ◽  
Radical Anion ◽  
Wittig Reaction ◽  
H Nmr ◽  
Trans Isomerization ◽  
Ct Complex

Mixtures of E- and Z-isomers of 1,2-bis(5-nitro-2-furyl)ethylene (I), 1-(5-nitro-2-furyl)-2-(4-nitrophenyl)ethylene (II), 1,2-bis(4-nitrophenyl)ethylene (III), 1-(5-methoxycarbonyl-2-furyl)-2-(4-nitrophenyl)ethylene (IV), 1-(5-methoxycarbonyl-2-furyl)-2-(5-nitro-2-furyl)ethylene (V) and 1-(5-methoxycarbonyl-2-furyl)-2-(5-nitro-2-thienyl)ethylene (VI) were prepared by the Wittig reaction. These derivatives were isomerized by electron transfer-induced reactions via the radical anion in the CT-complex using aniline as electron donor at 25 °C in the light or at 80 °C in the dark. The starting as well as the final E:Z ratio was determined by 1H NMR spectroscopy. In all cases only the cis → trans isomerization was observed.

One-Pot Synthesis of Lanthanide and Yttrium Cryptates Containing Pyridine Units

1997 ◽  
Vol 52 (10) ◽  
pp. 1273-1277 ◽  
Author(s):  
Fernando Avecilla ◽  
Rufina Bastida ◽  
Andrés de Blas ◽  
Eugenia Carrera ◽  
David E. Fenton ◽  
...  
Keyword(s):  
Schiff Base ◽  
Nmr Spectroscopy ◽  
Elemental Analysis ◽  
Molar Conductivity ◽  
One Pot ◽  
H Nmr ◽  
One Pot Synthesis ◽  
Step Procedure ◽  
One Step ◽  
High Yields

Complexes of yttrium (III) and lanthanide(III) ions with an axial macrobicycle derived from the 2+3 Schiff-base condensation of tris(2-aminoethyl)amine with 2,6-diformylpyridine have been prepared in high yields using a one-step procedure. The complexes, with formula [M2L](NO3)6 · xH2O · ySolv, (M = Y, La - Lu, except Pm) and [M 2L](ClO4)6 · xH2O · ySolv, (M = La - Er, except Pm ), have been characterised by elemental analysis, molar conductivity, mass, IR and 1H NMR spectroscopy.

n–π Electron donor–acceptor complexes. II. Aliphatic amines with dinitrobenzenes

1985 ◽  
Vol 63 (4) ◽  
pp. 903-907 ◽  
Author(s):  
Joaquín O. Singh ◽  
Jorge D. Anunziata ◽  
Juana J. Silber
Keyword(s):  
Electron Donor ◽  
Iterative Procedure ◽  
Steric Effect ◽  
Aliphatic Amines ◽  
Primary Amines ◽  
Substitution Reactions ◽  
Aromatic Nucleophilic Substitution ◽  
Donor Acceptor ◽  
Eda Complex ◽  
The Stability

The interaction of several aliphatic amines as n-donors and dinitrobenzenes (DNB) as π-acceptors has been studied in n-hexane. The formation of electron donor – acceptor (EDA) complexes is proposed to explain the spectroscopic behaviour of the mixtures. The stability constants (Ks) for these complexes have been calculated by an iterative procedure. For a given acceptor, the donor strength of RNH2 > R2NH > R3N was found. This order is explained by considering the role that steric effect may play in the EDA complex formation. On the other hand, the fact that for a given donor Ks follows the order 1,2-DNB > 1,3-DNB > 1,4-DNB, and that 1,2-DNB reacts with primary amines, led to the proposal of orientational complexes. These EDA complexes may be considered intermediates in aromatic nucleophilic substitution reactions.

Metal-Free Photoinduced Hydroalkylation Cascade Enabled by an Electron-Donor-Acceptor Complex

2020 ◽  
Author(s):  
José Tiago Menezes Correia ◽  
Gustavo Piva da Silva ◽  
Camila Menezes Kisukuri ◽  
Elias André ◽  
Bruno Pires ◽  
...  
Keyword(s):  
Electron Donor ◽  
Functional Group ◽  
Photoexcited Electron ◽  
One Pot ◽  
Quaternary Centers ◽  
Metal Free ◽  
Acceptor Complex ◽  
Catalyst Free ◽  
Donor Acceptor ◽  
Radical Cascade

A metal- and catalyst-free photoinduced radical cascade hydroalkylation of 1,7-enynes has been disclosed. The process is triggered by a SET event involving a photoexcited electron-donor-aceptor complex between NHPI ester and Hantzsch ester, which decomposes to afford a tertiary radical that is readily trapped by the enyne. <a>The method provides an operationally simple, robust and step-economical approach to the construction of diversely functionalized dihydroquinolinones bearing quaternary-centers. A sequential one-pot hydroalkylation-isomerization approach is also allowed giving access to a family of quinolinones. A wide substrate scope and high functional group tolerance was observed in both approaches</a>.

Sign in / Sign up

Export Citation Format

Share Document